In the prior art, removal of pavement for the purpose of repaving a road, dsriveway, etc. has required the use of several the operation, a front-end loader is utilized to pick up the pavement material and load it onto trucks for hauling to a site for disposal.
Thus, it is seen that there is a dire need in the art of pavement removal for a device which combines many of the functions described hereinabove into one self contained unit. Such a device would save the costs of renting or buying pieces of equipment such as front-end loaders and the like and would more efficiently and quickly remove and process the pavement material for re-use on a roadway.
The following prior art is known to applicant:
U.S. Pat. No. 145,153 to Conrad discloses a hand cultivator wherein a plurality of triangular tooth-like hoe blades are provided and between each hoe blade, a vertical rake element is provided in spaced relation therefrom. This device is vastly different from the invention disclosed herein in that (1) the hoe blades are disposed at right angles to the orientation of the inventive rippers herein and (2) the rake elements thereof are quite narrow in dimension and would not provide the interaction which exists between the rippers and hold-down pressure plate of the present invention.
U.S. Pat. No. 800,005 to McEwing discloses a blocking and cultivating machine having blocking shoes placed between the cultivator teeth. The blocking shoes sever the soil in each side of a row to be left and protect the row from soil thrown outwardly by the cultivator. The device disclosed by McEwing is vastly different from that of the present invention in that (1) the blocking shoes are designed to move with respect to the cultivators during the operation of the device whereas in the present invention the rippers and the hold down-pressure plate are designed to be rigidly spaced from one another during the operation thereof, and (2) there is no structure in McEwing even remotely resembling the control chamber, elevator and associated structure of the present invention.
U.S. Pat. No. 2,539,136 to Hite discloses a surface crusher towed behind a tractor. The main frame thereof carries a plurality of teeth having lower forwardly directed extensions and chisel shaped ends which cooperate with a crushing rotor having a plurality of elements disposed about an axle. These elements interdigitate with the above described teeth to break up locks. The main difference between this invention and the invention disclosed herein lies in the fact that the present invention includes fixed rippers in conjunction with a fixed hold-down pressure plate whereas the Hite invention utilizes a rotating rotor with a plurality of elements disposed thereabout which rotate during the operation of the device. This, of course, is vastly different from the teachings of the present invention.
U.S. Pat. No. 3,843,274 to Gutman, et al, discloses an asphalt reclaiming device wherein a rotary cutter with a plurality of teeth or blades is disposed transversely of the vehicle and behind a heater so as to cut up the heated asphalt and push it into a pugmill. The teeth are arranged in a spiral along the cutter shaft which also includes a continuous blade forming another spiral between the spiral of teeth (FIG. 4). Similarly to the above described U.S. patent to Hite, this patent includes the use of a rotary element for removal of the pavement whereas in the present invention, the hold-down pressure plate and the rippers are stationary with respect to one another.
U.S. Pat. No. 3,952,811 to Carre discIoses a rock crusher similar to the above discussed U.S. patent to Hite wherein a plurality of teeth or plowshares cooperate with a plurality of hammers disposed along the shaft of a rotor. As disclosed with regard to Hite, these hammers interdigitate with the plowshares to crush rocks and other material razed by the device. The differences between the present invention and Carre are the same as the differences between the present invention and Hite.
U.S. Pat. No. 4,322,178 to Lee discloses a pavement patching apparatus including a backhoe provided with a cutting blade at the back of the bucket and screeding edges underneath (FIG. 1). The cutting blade is used to cut into pavement when the bucket is tilted so that the open end thereof is pointed upwardly. FIG. 1 shows the blade in contact with the pavement and the rear ends of the screeding edges resting on the surface. This device is vastly different from the device disclosed herein in view of the variations in angle of attack of the bucket with respect to the pavement and further in view of the fact that Lee does not show any of the details of the control chamber, elevator and associated structure disclosed herein.